Open AccessHuman C-Reactive Protein Is Protective against FatalSalmonella entericaSerovar Typhimurium Infection in Transgenic Mice
Author(s) -
Alexander J. Szalai,
John L. VanCott,
Jerry R. McGhee,
John E. Volanakis,
William H. Benjamin
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.10.5652-5656.2000
Subject(s) - salmonella enterica , biology , microbiology and biotechnology , salmonella , antibody , immune system , pathogen , spleen , salmonella infection , serotype , virology , streptococcus pneumoniae , virulence , immunology , bacteria , antibiotics , gene , genetics , biochemistry
C-reactive protein (CRP) is an acute-phase protein with a well-known association with infection and other inflammatory conditions. We have shown that expression of human CRP by CRP transgenic (CRPtg) mice is protective against lethal infection by Streptococcus pneumoniae, an effect likely mediated by CRP's ability to bind to this gram-positive pathogen. In the present study we tested whether CRPtg mice are resistant to infection with Salmonella enterica serovar Typhimurium, a gram-negative pathogen that causes the murine equivalent of typhoid fever. CRPtg mice experimentally infected with a virulent Typhimurium strain lived longer and had significantly lower mortality than their non-tg littermates. The greater resistance of CRPtg mice could be attributed to significantly increased early (0 to 4 h) blood clearance of salmonellae and significantly decreased numbers of bacteria in the liver and spleen on day 7 postinfection. In addition, 14 days after infection with an avirulent Salmonella strain, the serum titer of anti-Salmonella immunoglobulin G antibodies was higher in CRPtg than non-tg mice. This study provides unequivocal evidence that CRP plays an important role in vivo in host defense against salmonellae during the early stages of infection. In addition, as the beneficial effect of CRP includes enhancement of the host's humoral immune response, CRP may also contribute indirectly to host defense during later stages of infection.